[#100] server auto re-binding

Signed-off-by: Pavel Pogodaev <p.pogodaev@yadro.com>

CHANGELOG.md

@@ -8,13 +8,15 @@ This document outlines major changes between releases.
 
 ### Added
 - Tree pool traversal limit (#92)
+- Add new `reconnect_interval` config param (#100)
 
 ### Update from 0.28.0
 See new `frostfs.tree_pool_max_attempts` config parameter.
 
 ### Fixed
 - Fix possibility of panic during SIGHUP (#99)
-- Handle query unescape and invalid bearer token errors (#108)
+- Handle query unescape and invalid bearer token errors (#107)
+- Fix HTTP/2 requests (#110)
 
 ### Added
 - Support client side object cut (#70)

cmd/http-gw/app.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net/http"
 	"os"
@@ -57,7 +58,10 @@ type (
 		metrics   *gateMetrics
 		services  []*metrics.Service
 		settings  *appSettings
+
 		servers       []Server
+		unbindServers []ServerInfo
+		mu            sync.RWMutex
 	}
 
 	// App is an interface for the main gateway function.
@@ -78,6 +82,8 @@ type (
 
 	// appSettings stores reloading parameters, so it has to provide getters and setters which use RWMutex.
 	appSettings struct {
+		reconnectInterval time.Duration
+
 		mu                  sync.RWMutex
 		defaultTimestamp    bool
 		zipCompression      bool
@@ -199,8 +205,9 @@ func (s *appSettings) setBufferMaxSizeForPut(val uint64) {
 }
 
 func (a *app) initAppSettings() {
-	a.settings = &appSettings{}
+	a.settings = &appSettings{
-
+		reconnectInterval: fetchReconnectInterval(a.cfg),
+	}
 	a.updateSettings()
 }
 
@@ -399,16 +406,22 @@ func (a *app) Serve() {
 	a.startServices()
 	a.initServers(a.ctx)
 
-	for i := range a.servers {
+	servs := a.getServers()
+
+	for i := range servs {
 		go func(i int) {
-			a.log.Info(logs.StartingServer, zap.String("address", a.servers[i].Address()))
+			a.log.Info(logs.StartingServer, zap.String("address", servs[i].Address()))
-			if err := a.webServer.Serve(a.servers[i].Listener()); err != nil && err != http.ErrServerClosed {
+			if err := a.webServer.Serve(servs[i].Listener()); err != nil && err != http.ErrServerClosed {
-				a.metrics.MarkUnhealthy(a.servers[i].Address())
+				a.metrics.MarkUnhealthy(servs[i].Address())
 				a.log.Fatal(logs.ListenAndServe, zap.Error(err))
 			}
 		}(i)
 	}
 
+	if len(a.unbindServers) != 0 {
+		a.scheduleReconnect(a.ctx, a.webServer)
+	}
+
 	sigs := make(chan os.Signal, 1)
 	signal.Notify(sigs, syscall.SIGHUP)
 
@@ -598,7 +611,7 @@ func (a *app) AppParams() *utils.AppParams {
 }
 
 func (a *app) initServers(ctx context.Context) {
-	serversInfo := fetchServers(a.cfg)
+	serversInfo := fetchServers(a.cfg, a.log)
 
 	a.servers = make([]Server, 0, len(serversInfo))
 	for _, serverInfo := range serversInfo {
@@ -608,6 +621,7 @@ func (a *app) initServers(ctx context.Context) {
 		}
 		srv, err := newServer(ctx, serverInfo)
 		if err != nil {
+			a.unbindServers = append(a.unbindServers, serverInfo)
 			a.metrics.MarkUnhealthy(serverInfo.Address)
 			a.log.Warn(logs.FailedToAddServer, append(fields, zap.Error(err))...)
 			continue
@@ -624,22 +638,25 @@ func (a *app) initServers(ctx context.Context) {
 }
 
 func (a *app) updateServers() error {
-	serversInfo := fetchServers(a.cfg)
+	serversInfo := fetchServers(a.cfg, a.log)
+
+	a.mu.Lock()
+	defer a.mu.Unlock()
 
 	var found bool
 	for _, serverInfo := range serversInfo {
-		index := a.serverIndex(serverInfo.Address)
+		ser := a.getServer(serverInfo.Address)
-		if index == -1 {
+		if ser != nil {
-			continue
-		}
-
 			if serverInfo.TLS.Enabled {
-			if err := a.servers[index].UpdateCert(serverInfo.TLS.CertFile, serverInfo.TLS.KeyFile); err != nil {
+				if err := ser.UpdateCert(serverInfo.TLS.CertFile, serverInfo.TLS.KeyFile); err != nil {
 					return fmt.Errorf("failed to update tls certs: %w", err)
 				}
-		}
 				found = true
 			}
+		} else if unbind := a.updateUnbindServerInfo(serverInfo); unbind {
+			found = true
+		}
+	}
 
 	if !found {
 		return fmt.Errorf("invalid servers configuration: no known server found")
@@ -648,13 +665,29 @@ func (a *app) updateServers() error {
 	return nil
 }
 
-func (a *app) serverIndex(address string) int {
+func (a *app) getServers() []Server {
+	a.mu.RLock()
+	defer a.mu.RUnlock()
+	return a.servers
+}
+
+func (a *app) getServer(address string) Server {
 	for i := range a.servers {
 		if a.servers[i].Address() == address {
-			return i
+			return a.servers[i]
 		}
 	}
-	return -1
+	return nil
+}
+
+func (a *app) updateUnbindServerInfo(info ServerInfo) bool {
+	for i := range a.unbindServers {
+		if a.unbindServers[i].Address == info.Address {
+			a.unbindServers[i] = info
+			return true
+		}
+	}
+	return false
 }
 
 func (a *app) initTracing(ctx context.Context) {
@@ -727,3 +760,60 @@ func (s *appSettings) setDefaultNamespaces(namespaces []string) {
 	s.defaultNamespaces = namespaces
 	s.mu.Unlock()
 }
+
+func (a *app) scheduleReconnect(ctx context.Context, srv *fasthttp.Server) {
+	go func() {
+		t := time.NewTicker(a.settings.reconnectInterval)
+		defer t.Stop()
+		for {
+			select {
+			case <-t.C:
+				if a.tryReconnect(ctx, srv) {
+					return
+				}
+				t.Reset(a.settings.reconnectInterval)
+			case <-ctx.Done():
+				return
+			}
+		}
+	}()
+}
+
+func (a *app) tryReconnect(ctx context.Context, sr *fasthttp.Server) bool {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+
+	a.log.Info(logs.ServerReconnecting)
+	var failedServers []ServerInfo
+
+	for _, serverInfo := range a.unbindServers {
+		fields := []zap.Field{
+			zap.String("address", serverInfo.Address), zap.Bool("tls enabled", serverInfo.TLS.Enabled),
+			zap.String("tls cert", serverInfo.TLS.CertFile), zap.String("tls key", serverInfo.TLS.KeyFile),
+		}
+
+		srv, err := newServer(ctx, serverInfo)
+		if err != nil {
+			a.log.Warn(logs.ServerReconnectFailed, zap.Error(err))
+			failedServers = append(failedServers, serverInfo)
+			a.metrics.MarkUnhealthy(serverInfo.Address)
+			continue
+		}
+
+		go func() {
+			a.log.Info(logs.StartingServer, zap.String("address", srv.Address()))
+			a.metrics.MarkHealthy(serverInfo.Address)
+			if err = sr.Serve(srv.Listener()); err != nil && !errors.Is(err, http.ErrServerClosed) {
+				a.log.Warn(logs.ListenAndServe, zap.Error(err))
+				a.metrics.MarkUnhealthy(serverInfo.Address)
+			}
+		}()
+
+		a.servers = append(a.servers, srv)
+		a.log.Info(logs.ServerReconnectedSuccessfully, fields...)
+	}
+
+	a.unbindServers = failedServers
+
+	return len(a.unbindServers) == 0
+}

cmd/http-gw/server.go

@@ -74,6 +74,7 @@ func newServer(ctx context.Context, serverInfo ServerInfo) (*server, error) {
 
 		ln = tls.NewListener(ln, &tls.Config{
 			GetCertificate: tlsProvider.GetCertificate,
+			NextProtos:     []string{"h2"}, // required to enable HTTP/2 requests in `http.Serve`
 		})
 	}
 

cmd/http-gw/server_test.go

@@ -0,0 +1,119 @@
+package main
+
+import (
+	"context"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"fmt"
+	"math/big"
+	"net"
+	"net/http"
+	"os"
+	"path"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"golang.org/x/net/http2"
+)
+
+const (
+	expHeaderKey   = "Foo"
+	expHeaderValue = "Bar"
+)
+
+func TestHTTP2TLS(t *testing.T) {
+	ctx := context.Background()
+	certPath, keyPath := prepareTestCerts(t)
+
+	srv := &http.Server{
+		Handler: http.HandlerFunc(testHandler),
+	}
+
+	tlsListener, err := newServer(ctx, ServerInfo{
+		Address: ":0",
+		TLS: ServerTLSInfo{
+			Enabled:  true,
+			CertFile: certPath,
+			KeyFile:  keyPath,
+		},
+	})
+	require.NoError(t, err)
+	port := tlsListener.Listener().Addr().(*net.TCPAddr).Port
+	addr := fmt.Sprintf("https://localhost:%d", port)
+
+	go func() {
+		_ = srv.Serve(tlsListener.Listener())
+	}()
+
+	// Server is running, now send HTTP/2 request
+
+	tlsClientConfig := &tls.Config{
+		InsecureSkipVerify: true,
+	}
+
+	cliHTTP1 := http.Client{Transport: &http.Transport{TLSClientConfig: tlsClientConfig}}
+	cliHTTP2 := http.Client{Transport: &http2.Transport{TLSClientConfig: tlsClientConfig}}
+
+	req, err := http.NewRequest("GET", addr, nil)
+	require.NoError(t, err)
+	req.Header[expHeaderKey] = []string{expHeaderValue}
+
+	resp, err := cliHTTP1.Do(req)
+	require.NoError(t, err)
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+
+	resp, err = cliHTTP2.Do(req)
+	require.NoError(t, err)
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+}
+
+func testHandler(resp http.ResponseWriter, req *http.Request) {
+	hdr, ok := req.Header[expHeaderKey]
+	if !ok || len(hdr) != 1 || hdr[0] != expHeaderValue {
+		resp.WriteHeader(http.StatusBadRequest)
+	} else {
+		resp.WriteHeader(http.StatusOK)
+	}
+}
+
+func prepareTestCerts(t *testing.T) (certPath, keyPath string) {
+	privateKey, err := rsa.GenerateKey(rand.Reader, 2048)
+	require.NoError(t, err)
+
+	template := x509.Certificate{
+		SerialNumber:          big.NewInt(1),
+		Subject:               pkix.Name{CommonName: "localhost"},
+		NotBefore:             time.Now(),
+		NotAfter:              time.Now().Add(time.Hour * 24 * 365),
+		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
+		BasicConstraintsValid: true,
+	}
+
+	derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &privateKey.PublicKey, privateKey)
+	require.NoError(t, err)
+
+	dir := t.TempDir()
+	certPath = path.Join(dir, "cert.pem")
+	keyPath = path.Join(dir, "key.pem")
+
+	certFile, err := os.Create(certPath)
+	require.NoError(t, err)
+	defer certFile.Close()
+
+	keyFile, err := os.Create(keyPath)
+	require.NoError(t, err)
+	defer keyFile.Close()
+
+	err = pem.Encode(certFile, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
+	require.NoError(t, err)
+
+	err = pem.Encode(keyFile, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(privateKey)})
+	require.NoError(t, err)
+
+	return certPath, keyPath
+}

cmd/http-gw/settings.go

@@ -51,11 +51,15 @@ const (
 
 	defaultNamespaceHeader = "X-Frostfs-Namespace"
 
+	defaultReconnectInterval = time.Minute
+
 	cfgServer      = "server"
 	cfgTLSEnabled  = "tls.enabled"
 	cfgTLSCertFile = "tls.cert_file"
 	cfgTLSKeyFile  = "tls.key_file"
 
+	cfgReconnectInterval = "reconnect_interval"
+
 	// Web.
 	cfgWebReadBufferSize     = "web.read_buffer_size"
 	cfgWebWriteBufferSize    = "web.write_buffer_size"
@@ -454,8 +458,18 @@ func getLogLevel(v *viper.Viper) (zapcore.Level, error) {
 	return lvl, nil
 }
 
-func fetchServers(v *viper.Viper) []ServerInfo {
+func fetchReconnectInterval(cfg *viper.Viper) time.Duration {
+	reconnect := cfg.GetDuration(cfgReconnectInterval)
+	if reconnect <= 0 {
+		reconnect = defaultReconnectInterval
+	}
+
+	return reconnect
+}
+
+func fetchServers(v *viper.Viper, log *zap.Logger) []ServerInfo {
 	var servers []ServerInfo
+	seen := make(map[string]struct{})
 
 	for i := 0; ; i++ {
 		key := cfgServer + "." + strconv.Itoa(i) + "."
@@ -470,6 +484,11 @@ func fetchServers(v *viper.Viper) []ServerInfo {
 			break
 		}
 
+		if _, ok := seen[serverInfo.Address]; ok {
+			log.Warn(logs.WarnDuplicateAddress, zap.String("address", serverInfo.Address))
+			continue
+		}
+		seen[serverInfo.Address] = struct{}{}
 		servers = append(servers, serverInfo)
 	}
 

config/config.env

@@ -26,6 +26,9 @@ HTTP_GW_SERVER_1_TLS_ENABLED=true
 HTTP_GW_SERVER_1_TLS_CERT_FILE=/path/to/tls/cert
 HTTP_GW_SERVER_1_TLS_KEY_FILE=/path/to/tls/key
 
+# How often to reconnect to the servers
+HTTP_GW_RECONNECT_INTERVAL: 1m
+
 # Nodes configuration.
 # This configuration make the gateway use the first node (grpc://s01.frostfs.devenv:8080)
 # while it's healthy. Otherwise, the gateway use the second node (grpc://s01.frostfs.devenv:8080)

config/config.yaml

@@ -55,6 +55,7 @@ peers:
     priority: 2
     weight: 9
 
+reconnect_interval: 1m
 
 web:
   # Per-connection buffer size for requests' reading.

docs/gate-configuration.md

@@ -72,6 +72,7 @@ stream_timeout: 10s
 request_timeout: 5s
 rebalance_timer: 30s
 pool_error_threshold: 100
+reconnect_interval: 1m
 ```
 
 | Parameter              | Type       | SIGHUP reload | Default value  | Description                                                                        |
@@ -83,6 +84,7 @@ pool_error_threshold: 100
 | `request_timeout`      | `duration` |               | `15s`          | Timeout to check node health during rebalance.                                     |
 | `rebalance_timer`      | `duration` |               | `60s`          | Interval to check node health.                                                     |
 | `pool_error_threshold` | `uint32`   |               | `100`          | The number of errors on connection after which node is considered as unhealthy.    |
+| `reconnect_interval`   | `duration` | no            | `1m`           | Listeners reconnection interval.                                                   |
 
 # `wallet` section
 

go.mod

@@ -22,6 +22,7 @@ require (
 	go.opentelemetry.io/otel/trace v1.16.0
 	go.uber.org/zap v1.24.0
 	golang.org/x/exp v0.0.0-20230515195305-f3d0a9c9a5cc
+	golang.org/x/net v0.10.0
 	google.golang.org/grpc v1.55.0
 )
 
@@ -103,7 +104,6 @@ require (
 	go.uber.org/atomic v1.10.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	golang.org/x/crypto v0.9.0 // indirect
-	golang.org/x/net v0.10.0 // indirect
 	golang.org/x/sync v0.2.0 // indirect
 	golang.org/x/sys v0.8.0 // indirect
 	golang.org/x/term v0.8.0 // indirect

internal/logs/logs.go

@@ -73,4 +73,8 @@ const (
 	InvalidLifetimeUsingDefaultValue                                      = "invalid lifetime, using default value (in seconds)"                                     // Error in ../../cmd/http-gw/settings.go
 	InvalidCacheSizeUsingDefaultValue                                     = "invalid cache size, using default value"                                                // Error in ../../cmd/http-gw/settings.go
 	FailedToUnescapeQuery                                                 = "failed to unescape query"
+	ServerReconnecting                                                    = "reconnecting server..."
+	ServerReconnectedSuccessfully                                         = "server reconnected successfully"
+	ServerReconnectFailed                                                 = "failed to reconnect server"
+	WarnDuplicateAddress                                                  = "duplicate address"
 )